A structure is known in which a marker for identification or management is formed on a mask blank glass substrate for use in the manufacture of a mask blank (see, e.g. Japanese Unexamined Patent Application Publication (JP-A) No. 2006-309143 (Patent Document 1) corresp. to US2006/0246361A1). This marker is expressed by an array of pits. The pits are formed by laser light irradiation on a surface of a region, having no influence on formation of a transfer pattern, of a mask blank glass substrate, for example, on a main surface in a peripheral region outside a region where a transfer pattern is formed in a mask blank fabricated by forming a transfer pattern thin film on the mask blank glass substrate, on an end face, on a chamfered surface formed between the main surface and the end face, or on a notch mark forming portion.